Platform for mounting a ski binding on a ski

ABSTRACT

A platform is foreseen according to the invention by which an elastically deformable base plate ( 11 ) is adapted to receive a front positioning plate ( 12 ) as well as a rear positioning plate ( 13 ), which are both positioned on the base plate ( 11 ) depending on each desired position of both assemblies ( 71, 72 ) of a ski binding ( 7 ). Since the platform should allow a freely bending of a ski ( 5 ) by enabling simultaneously an efficient dampening of vibrations, a front bearing plate ( 2 ) is foreseen on the front positioning plate ( 12 ) for the purposes of bearing a front assembly ( 71 ) of the ski binding, and is attached to the front positioning plate by means of a pair of levers ( 21, 22 ), which are pivotally connected to the positioning plate and to the bearing plate. A rear bearing plate ( 3 ) is foreseen on the rear positioning plate and is attached to the rear positioning plate by means of a pair of levers ( 31,   32 ), which are pivotally connected to the positioning plate and to the bearing plate.

The invention relates to the improved platform for fixing a ski binding to a ski. According to an international patent classification, the invention of this kind belongs to the area of skis and/or ski bindings, and at the same time to the elements provided for the damping of vibrations while the ski slides across the surface.

Specifically, the invention relates to the platform that can be subsequently mounted on the upper surface of the previously finalized ski while to said platform a ski binding can then be fixed, namely the front or finger assembly and the rear or heel assembly of said ski binding which hold an available ski boot in the central area above the upper ski surface during use. During the skiing the ski as the bending holder of certain width very frequently and significantly bends, which generally leads to deformations on its surface, namely to elongations or contractions on the lower gliding surface on which, or at least in whose direct vicinity, said platform, both parts of the ski binding and a ski boot can be found. Furthermore, during the use of the ski either said bending deformations or other mechanical influences often lead to vibrations of the ski which negatively impact the manageability of the ski in each desired direction.

Considering the above, the invention is based on the problem of how to design a platform which will, after being fixed to the upper ski surface, ensure the required, even relatively small standing height if so desired, and facilitate an unobstructed bending of the ski while ensuring the damping of vibrations, during which the ski boot will be held in an unchangeable position in spite of the extreme bending of the ski and during which the distance between both parts of the ski binding will remain practically unchangeable even during the extreme bending of the ski.

In DE 9317689U (ROSSIGNOL SA) there is a ski on whose upper side a platform is fixed, consisting of rigid and viscoelastic layers placed one above the other, with the viscoelastic layer being the bottom one. Such a platform facilitates the fixing of both parts of the ski binding at the suitable distance from the upper ski surface and thus ensures the desired standing height. The latter can also be very small, which is convenient for racing skis which have to comply with the regulations. At the same time such a platform facilitates the damping of some vibrations, those which are transferred from the ski to the skier's leg thereby applying pressure on the skier. On the other hand, due to the rigid layer such a platform significantly restricts bending of the ski and during the application of pressure it changes the course of the bending line. Consequently, the transmission of forces on each active edge is uneven and because of that a significant part of the edge is practically inactive during the turn, which definitely impacts the adherence and manageability of the ski during the turn. The influence of such a platform on the damping of the oscillation of the ski itself is only negligible or at least insufficient and for this reason at each application of pressure the ski can oscillate relatively unobstructedly and gradually, which definitely impacts the pressure on each active edge and thus the manageability of the ski during the turn and while exiting the turn. Furthermore, the bending deformations of the ski on the upper surface of said ski and also on the surface of such a platform result in an elongated or contracted distance between the front and rear part of the ski binding. Such deformations in the longitudinal direction during the extreme bending pressure on the ski can amount up to 1 centimeter and should in principle be compensated for by at least the most perfected ski bindings. Theoretically this is true, but in practice e.g. during a race such deformations follow each other so quickly that spring-loaded elements of ski bindings cannot keep up with the changes, which results in a disconnection between the ski boot and the ski binding, thus separating the ski boot from the ski.

Furthermore, in JP 8257199 (OGASAKA SKI SEISAKUSHO) a platform was proposed which is also fixable to the finalized ski and provides for the desired standing height, which can be relatively small, and the fixing of both parts of the binding as well as an unobstructed bending of the ski. Such a platform is basically designed as a plate made of a material based on synthetic resins which in the central area between the locations for the fixing of both ski binding parts includes a zigzag weak spot consisting of lateral ribs and grooves. Even though such a platform actually facilitates an unobstructed bending of the ski and thus a corresponding distribution of pressure along the whole active length of each active edge, the problem of the compensation of bending deformations on the ski surface despite all other advantages still persists.

EP 1 031 360 (Bünter R.) proposes a platform which consists of a rigid plate and a pair of axial vibration dampers each of which has an articulated connection to said plate on one side and to the corresponding flange, which is fixed on the upper ski surface in its central part, on the other side. Said plate extends longitudinally along the ski and the dampers are situated in said direction one after another. Thanks to a two-point anchorage of the platform, such a design should facilitate an unobstructed bending of the ski and an efficient damping of vibrations and at the same time a possible tilt of the platform in the downward and forward directions. The latter can be favourable in certain siding styles or disciplines, especially e.g. downhill. However, the problem of the compensation of bending deformations during the extreme bending of the ski remains unsolved with this platform.

Moreover, in U.S. Pat. No. 6,513,826 B1 (Hangl A.) a platform is described, consisting of leading plates fixed to the ski to which fixing plates are mounted, each of which is adapted to receive one part of the ski binding and one of which is, thanks to two longitudinal grooves, adjustable longitudinally. Said fixing plates are then connected to each other with a longitudinal binding which also, if necessary, facilitates the change in the distance between the fixing plates, namely the adjustment of this distance to the size of the ski boot. Such a platform also facilitates the required standing height. The vibration damping occurs to a certain extent because of the friction during the shifting of the longitudinally adjustable fixing plate along the leading plate, which is a result of the bending of the ski. Both desired qualities, namely allowing the ski to bend and damping the vibrations, contradict each other in this solution—when one of them is more distinctive, the other plays a more marginal role and vice versa. On the other hand, there is also a problem that the forces which affect the ski normally, i.e. perpendicularly to the longitudinal direction, and cause the bending and vibrations or deformations which are a result of those forces are redirected in the grooves of the leading plate from said normal direction to the longitudinal direction, which results in a significant friction and high local load to the parts in said area, which in practical use in turn leads to a significant obstruction of free bending of the ski on the one hand and enormous wear of the parts in said area on the other hand.

Furthermore, in SI 21309 A (Sitar F.) there is a solution of the platform consisting of a pair of fixing elements spaced apart in the longitudinal direction of the ski which are separately screwed to the ski and over which a connective plate is placed with the front and the rear part of the ski binding being fixed to it. The connective plate is fixed to said elements fixed in elastic assemblies each of which is comprised of an elastic insertion and a fixing screw. Said assemblies are intended for damping of vibrations which are transferred from the ski to the skier's legs. In one of the constructions, which facilitates an unobstructed bending of the ski, the connective plate is pivotally connected on one side to one of the fixing elements fixed to the ski which is linked to said connective plate on one side and corresponding fixing element on the other side using articulated rocker arms. On the opposite end the connective plate is turnably linked to the corresponding fixing element with a suitable bolt. In this case the elastic assemblies for vibration damping are available in fixing elements while the articulated linkage between the plate and the fixing element facilitates, at least in limited extent, a compensation of deformations on the upper surface of the ski. In spite of the above measures such a platform in certain states of pressure can affect the course of the bending line of the ski and in turn the distribution of the pressure along each active edge and consequently also the manageability of the ski in the desired direction.

The invention relates to the platform for fixing the ski binding to the ski, consisting of a fixing assembly, which is comprised of at least a base plate which is adapted to be fixed to the upper surface of the ski in each selected area for fixing the ski binding, while said fixing assembly is adapted to hold the ski boot in the desired position of the intended front assembly and rear assembly of the ski binding.

It is typical for the platform according to the invention that the elastically deformable base plate is adapted to receive the front positioning plate and the rear positioning plate whose positions on said base plate can be selected depending on each desired position of both ski binding assemblies, especially depending on the size of each available ski boot. Furthermore, on the front positioning plate a front bearing plate is foreseen which receives the front ski binding assembly and is linked with the front positioning plate with a pair of levers which are pivotally connected via pivot joints to the corresponding positioning plate on one side and via pivot joints to said bearing plate on the other side, namely the inner and outer levers. At the same time, on the rear positioning plate the rear bearing plate is intended, adapted to receive the rear ski binding assembly and is linked with the rear positioning plate with a pair of levers which are pivotally connected via pivot joints to the corresponding positioning plate on one side and via pivot joints to said bearing plate on the other side, namely the inner and outer levers.

The inner lever pivot joint and the outer lever pivot joint on the front positioning plate are preferentially situated on the line which extends in the longitudinal direction of the ski, the outer lever pivot joint on the front bearing plate is situated below said line while the inner lever pivot joint on the front bearing plate is situated below said line of the bend-undeformed ski and above said line of the bend-deformed ski. Quite analogously, the inner lever pivot joint and the outer lever pivot joint on the rear positioning plate are situated on the line which extends at least approximately in the longitudinal direction of the ski, the outer lever pivot joint on the rear bearing plate is situated below said line while the inner lever pivot joint on the rear bearing plate is situated below said line of the bend-undeformed ski and above said line of the bend-deformed ski.

Furthermore, each lever is designed either as a suitably rigid uniform lever or it consists of at least two rigidly connected blades or levers, which are and at the same time turnable around the same axes.

Furthermore, said one-piece or multi-piece base plate of the platform according to the invention preferentially consists of at least one longitudinal guide in whose area the front positioning plate and the rear positioning plate, which can be moved along said guide and then fixed to each selected position, are fixed to the base plate. To fix the positioning plates to each selected position, a series of suitably placed holes in the base plate is preferentially intended which are adjusted to receive suitable screws to fix each positioning plate.

The invention will be concretized with an example of the construction which is illustrated on the enclosed figure depicting

FIG. 1 a platform for mounting a ski binding to the ski in the mounted state on the ski with no pressure applied and together with the ski binding and the ski boot, in front view;

FIG. 2 a platform in FIG. 1 in top view;

FIG. 3 a more detailed view, of the front part of the platform on a ski with no pressure applied as in FIG. 1;

FIG. 4 a more detailed view of the rear part of the platform on a ski with no pressure applied as in FIG. 1:

FIG. 5 a platform for the fixing of the ski binding to the ski in the mounted state on the ski with pressure applied and together with the ski binding and the ski boot, in front view;

FIG. 6 a more detailed view of the front part of the platform on a ski with pressure applied as in FIG. 5;

FIG. 7 a more detailed view of the rear part of the platform on a ski with pressure applied as in FIG. 5.

The platform according to the invention consists of the fixing assembly 1 which is fixed on the upper surface 50 of the ski 5 when the platform is mounted and of the front bearing plate 2 and the rear bearing plate 3 of which each is pivotally connected to said fixing assembly 1 with a pair of levers 21, 33; 31, 32.

Each of said bearing plates 2, 3 is on its upper surface 20, 30 adapted for fixing each corresponding assembly 71, 72 of the ski binding 7. In the shown example the front assembly 71 of the ski binding 7 is fixed on the upper surface 20 of the front bearing plate 2 and it also consists of, among others, a spring-loaded holding element 710 into which a ski boot 6 is mounted. Furthermore, the rear assembly 72 of the ski binding 7 is fixed on the upper surface 30 of the rear bearing plate 3 and it also consists of, among others, a spring-loaded holding element 720 into which a ski boot 6 is mounted. Said elements 710, 720 of the binding 7 are, as stated, spring-loaded and pushed toward the boot 6 with a predefined force, and at the same time they are capable of maintaining this force in spite of relatively small changes in the distance between each other.

The fixing assembly 1 of the platform according to the invention consists of elastically deformable base plate 11 which is either one-piece or multi-piece and is fixed to the upper surface 50 of the ski 5, as well as of positioning plates 12, 13 which can be shifted along the longitudinal direction of the ski 5 along the suitable guides 112, 113 of the base plate and in the shown case fixable, using a series of suitably places holes 114 and corresponding screws 114, in each selected position depending on the size of each used ski boot 6.

Deformability of said base plate 11 is such that even after the fixing of the plate 11 on the ski 5 the bending of the ski is still unobstructed, which means that after the fixing of the base plate 11 on the ski 5 the bending rigidity of the ski 5 practically does not change. For this purpose the base plate 11 includes, at least in the central area 110, at least one bending weak spot 111.

As already mentioned, the front bearing plate 2 and the rear bearing plate 3 are linked, with assemblies 71, 72 fixed to them by each pair of levers 21, 22; 31, 32 pivotally connected to the fixing assembly 1, namely to positioning plates 12, 13 which are fixed, corresponding to the size of the ski boot 6, fixed to the base plate 11 of the fixing assembly 1 at each selected distance.

An expert will understand that each of the levers 21, 22; 31, 32 can mean, at least for the purpose of understanding this invention, either a uniform and sufficiently rigid lever or a composed lever which is formed of a series of at least approximately parallelly spaced and sufficiently rigidly connected blades or levers which are simultaneously turnable around one common axis.

Furthermore, for the purposes of understanding of the invention it is assumed that the expression inner levers 21, 31 defines levers closest to each other of the front bearing plate 2 and the rear bearing plate 3 while the expression outer levers 22, 32 defines the levers furthest apart from each other of the front bearing plate 2 and the rear bearing plate 3.

For the purpose of fixing the front bearing plate 2 to the corresponding positioning plate 12 with said levers 21, 22, two pivot joints 210, 220, found on the line L₂ which extends at least approximately in the longitudinal direction of the ski 5 and therefore each time at at least approximately even distance from the neutral bending line of the ski 5 regardless of whether the latter is bend-deformed (FIG. 5) or not (FIG. 1), are intended for the mounting of said levers 21, 22 on the positioning plate 12. The outer lever 22 is on one side turnably secured in said pivot joint 220 on the corresponding positioning plate 12 and on the other side also turnably secured in the pivot joint 202 on the front bearing plate 2, with the pivot joint 202 being situated below the line L₂ which connects both pivot joints 210, 220 of the levers 21, 22 on the front positioning plate 12. At the same time, the inner lever 21 is on one side turnably secured in said pivot joint 210 on the corresponding positioning plate 12 and on the other side also turnably secured in the pivot joint 201 on the front bearing plate 2, with the pivot joint 202 on the bend-undeformed ski 5 being situated below the line L₂ which connects both pivot joints of the levers 21, 22 on the front positioning plate 12 (FIG. 1), and on the bend-deformed ski 5 above said line L₂ (FIG. 5).

Quite analogously, for the purpose of fixing the rear bearing plate 3 to the corresponding positioning plate 13 with said levers 31, 32, two pivot joints 310, 320, found on the line L₃ which extends at least approximately in the longitudinal direction of the ski 5 and therefore each time at at least approximately even distance from the neutral bending line of the ski 5 regardless of whether the latter is bend-deformed (FIG. 5) or not (FIG. 1), are intended for the mounting of said levers 31, 32 on the positioning plate 13. The outer lever 32 is on one side turnably secured in said pivot joint 320 on the corresponding positioning plate 13 and on the other side also turnably secured in the pivot joint 302 on the rear bearing plate 3, with the pivot joint 302 being situated below the line L₃ which connects both pivot joints of the levers 31, 32 on the rear positioning plate 13. At the same time, the inner lever 31 is on one side turnably secured in said pivot joint 310 on the corresponding positioning plate 13 and on the other side also turnably secured in the pivot joint 302 on the rear bearing plate 3, with the pivot joint 302 on the bend-undeformed ski 5 being situated below the line L₃ which connects both pivot joints of the levers 31, 32 on the rear positioning plate 13 (FIG. 1), and on the bend-deformed ski 5 above said line L₃ (FIG. 5).

After the installation of the platform according to the invention, the fixing assembly 1 (FIG. 1) is fixed to the upper surface 50 of the ski 5 while the base plate 11 is fixed to the upper surface 50 of the ski 5, the front positioning plate 12 with the pivot joint 220 of the outer lever 22 and the pivot joint 210 of the inner lever 21 (FIGS. 2 and 4) and the rear positioning plate 13 with the pivot joint 320 of the outer lever 21 and the pivot joint 310 of the inner lever 31 (FIGS. 2 and 3) are fixed at a suitable distance from each other on the base plate 11. When the ski boot 6 is mounted between the holding elements 710, 720 of the front and rear parts 71, 72 of the ski binding 7, said elements 71, 720 are pushed towards the ski boot 6 each from its own side, and the bearing plates 2, 3 are thanks to skier's weight pushed to rest against the positioning plates 12, 13 after which the outer levers 23, 32 are found in an approximate vertical position and the inner levers 21, 31 in an approximate horizontal position, or to be more exact, in a slightly deflected position below the lines L₂, L₃ so that the pivot joints 201, 302 are found below said lines L₂, L₃. Such a state (FIGS. 1 through 4) corresponds either to a static state or a state of the ski 5 during skiing on a flat and smooth terrain when there is practically no pressure applied on the ski 5 and remains practically undeformed. In such a state the problems described in the introduction is in principle not that perceptible.

The problems arise when the ski 5 is exposed to at least static bending loads (FIG. 5) and especially to markedly dynamic loads and extreme deformations which are brought about in the turns, especially combined with fast skiing on an uneven terrain. FIG. 5 shows the same ski 5 with a mounted, platform in a state of extreme bending deformation.

As shown on FIG. 5, the base plate 1 readily follows the bending deformations of the ski 5 and deforms itself accordingly, practically with no impact or at least with no significant impact on the bending of the ski itself 5. Each of the positioning plates 12, 13 is fixed on its end of the base plate 11 and easily follows these deformations with an adequate turn from the previously discussed position to a position which corresponds to the deformed base plate 11 at that time.

The ski boot 6 is in principle rigid and cannot adapt to the deformations of the ski 5. In spite of the extreme bending deformation of the ski 5 and a significant reduction in length on the upper surface 50, the bearing plates 2, 3 together with the corresponding parts 71, 72 of the ski binding 7 with regard to the ski boot 6, thanks to the turning of the inner levers 21, 31, remain in an unchanged position parallel with the lower surface of the ski boot 6, which leads to a certain increase in the standing height with regard to the upper surface 50 of the deformed ski 5 which should in practice amount to up to 18 mm, and at the same time it helps maintain balance, which is of utmost importance during the turn.

Because of said reduction in length of the ski 5 in the area of its upper surface 50 as a result of bending deformations it would generally be expected that in spite of the turning of the inner lever 21, 31 the distance between parts 71, 72 of the ski binding 7 decreases, which should in theory be compensated for by the spring-loaded holding elements 710, 720, which in practice, notwithstanding this and the spring-loaded elements, leads to the effect of a wedge when the ski boot wedges between both assemblies 71, 72 of the ski binding 7, which then makes the bending of the ski more difficult. In the platform of this invention, such an effect is prevented thanks to the possibility of a turn of the outer lever 22, 32 around pivot joints 220, 320 which is sufficient for the compensation of said contractions on the surface 50 of the ski 5, which means that even during the extreme bending of the ski the distance between both assemblies 71, 72 of the binding 7 remains practically unchanged.

As already stated, the inner levers 21, 31 can be moved from the original position when the pivot joints 201, 301 are found below the lines L₂, L₃, to a deflected position when the pivot joints are found above the lines L₂, L₃ and vice versa. Because of the eccentric mounting of the bearing plates 12, 13 in the pivot joints 202, 302 which are turnably mounted in the pivot joints 220, 320 below the lines L₂, L₃, during the deformation of the ski 5 the pivot joints 201, 301 cross said lines, and then each crossing means a crossing over a dead point which instantly damps even the most disadvantageous vibrations when those occur. 

1. The platform for mounting ski binding (71) to the ski (5) consisting of a fixing assembly (1) which is comprised of at least a base plate (11), which is adapted to be fixed to the upper surface (50) of the ski (5) in each selected area for the fixing of the ski binding (7), and said fixing assembly (1) is adapted to receive and hold the ski boot (6) in the desired position of the intended front assembly (71) and the rear assembly (72) of the ski binding (7), characterized in that the elastically deformable base plate (11) is adapted to receive the front positioning plate (12) and the rear positioning plate (13) whose position on said base plate (11) can be chosen depending on the desired positions of both assemblies (71, 72) of the ski binding (7), that on the front positioning plate (12) the front bearing plate (2) is intended to receive the front assembly (71) of the ski binding (7) and is pivotally connected to the front positioning plate (12) with a pair of levers (21, 22), namely the inner lever (21) and the outer lever (22), which are mounted via pivot joints (210, 220) to the corresponding positioning plate (12) on one side and via pivot joints (201, 202) to said bearing plate (2) on the other side, and that on the rear positioning plate (13) the rear bearing plate (3) is intended to receive the rear assembly (72) of the ski binding (7) and is pivotally connected to the rear positioning plate (13) with a pair of levers (31, 32), namely the inner lever (31) and the outer lever (32), which are mounted via pivot joints (310, 320) to the corresponding positioning plate (12) on one side and via pivot joints (301, 302) to said bearing plate (3) on the other side.
 2. The platform of claim 1, characterized in that that the pivot joint (210) of the inner lever (21) and the pivot joint (220) of the outer lever (22) on the front positioning plate (12) are situated on the line (L₂) which extends at least approximately in the longitudinal direction of the ski (5), the pivot joint (202) of the outer lever (22) on the front bearing plate (2) is situated below said line (L₂), the pivot joint (201) of the inner lever (21) on the front bearing plate (2) is situated below said line (L₂) when the ski (5) is bend-undeformed, and above said line (L₂) when the ski (5) is bend-deformed, while the pivot joint (310) of the inner lever (31) and the pivot joint (320) of the outer lever (32) on the rear positioning plate (13) are situated on the line (L₃) which extends at least approximately in the longitudinal direction of the ski (5), the pivot joint (302) of the outer lever (32) on the rear bearing plate (3) is situated below said line (L₃), the pivot joint (301) of the inner lever (31) on the rear bearing plate (3) is situated below said line (L₃) when the ski (5) is bend-undeformed, and above said line (L₃) when the ski (5) is bend-deformed.
 3. The platform of claim 1 or 2, characterized in that that each lever (21, 22; 31, 32) is designed as a suitably rigid uniform lever.
 4. The platform of claim 1 or 2, characterized in that that each lever (21, 22; 31, 32) consists of at least two rigidly connected blades or levers which can be simultaneously turned around the same axes.
 5. The platform of one of the previous claims, characterized in that that the one-piece or multi-piece base plate (11) consists of at least one longitudinal guide (112, 113) in the area of which the rear positioning plate (12) and the rear positioning plate (13), which can be moved along said guide (112, 113) and then fixed in each selected position, are fixed to the base plate
 6. The platform of claim 5, characterized in that for the fixing of positioning plates (112, 113) to each selected position on the base plate (11), a series of suitably spaced holes (114) in the base plate (11) is intended, adapted to receive corresponding screws (115) to fix each positioning plate (12, 13). 